Revised patch to convert MessageID in smb2_hdr to LE

Revised patch to convert MessageID in smb2_hdr to LE

[Steve French]

Sachin,
Since your patch had various sparse warnings, I did a different
version, basically converting the SMB2/SMB3 MessageID field on the
wire  to le64 from u64 (we used to assume that the MessageId/MID was
opaque) and then modifying places that used it to match that
endianness.

Would you try that and make sure it works in your big endian
reproduction scenario (or propose an alternate patch)?



-- 
Thanks,

Steve

Re: Revised patch to convert MessageID in smb2_hdr to LE

[Steve French]

[-- Attachment #1: Type: text/plain, Size: 4860 bytes --]

Resending (attaching patch)

Redhat had encountered a problem with the SMB2/SMB3 message id (mid)
on PPC - the message id was being considered opaque and endian neutral.
Change the SMB2/SMB3 message id to be le64 on the wire (as we already
do with cifs).

Signed-off-by: Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
CC: Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 fs/cifs/smb2misc.c      | 12 +++++++-----
 fs/cifs/smb2ops.c       |  2 +-
 fs/cifs/smb2pdu.h       |  2 +-
 fs/cifs/smb2transport.c |  4 ++--
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 1a08a34..6e01933 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -32,12 +32,14 @@
 static int
 check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
 {
+    __u64 wire_mid = le64_to_cpu(hdr->MessageId);
+
     /*
      * Make sure that this really is an SMB, that it is a response,
      * and that the message ids match.
      */
     if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
-        (mid == hdr->MessageId)) {
+        (mid == wire_mid)) {
         if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
             return 0;
         else {
@@ -51,11 +53,11 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
         if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
             cifs_dbg(VFS, "Bad protocol string signature header %x\n",
                  *(unsigned int *) hdr->ProtocolId);
-        if (mid != hdr->MessageId)
+        if (mid != wire_mid)
             cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
-                 mid, hdr->MessageId);
+                 mid, wire_mid);
     }
-    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
+    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
     return 1;
 }

@@ -95,7 +97,7 @@ smb2_check_message(char *buf, unsigned int length)
 {
     struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
     struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
-    __u64 mid = hdr->MessageId;
+    __u64 mid = le64_to_cpu(hdr->MessageId);
     __u32 len = get_rfc1002_length(buf);
     __u32 clc_len;  /* calculated length */
     int command;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 568f323..e5b33d0 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -179,7 +179,7 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf)

     spin_lock(&GlobalMid_Lock);
     list_for_each_entry(mid, &server->pending_mid_q, qhead) {
-        if ((mid->mid == hdr->MessageId) &&
+        if ((mid->mid == le64_to_cpu(hdr->MessageId)) &&
             (mid->mid_state == MID_REQUEST_SUBMITTED) &&
             (mid->command == hdr->Command)) {
             spin_unlock(&GlobalMid_Lock);
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index d84f46c..2d6d388 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -110,7 +110,7 @@ struct smb2_hdr {
     __le16 CreditRequest;  /* CreditResponse */
     __le32 Flags;
     __le32 NextCommand;
-    __u64  MessageId;    /* opaque - so can stay little endian */
+    __le64  MessageId;    /* opaque - so can stay little endian */
     __le32 ProcessId;
     __u32  TreeId;        /* opaque - so do not make little endian */
     __u64  SessionId;    /* opaque - so do not make little endian */
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 5111e72..6bdee1b5 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -468,7 +468,7 @@ smb2_seq_num_into_buf(struct TCP_Server_Info
*server, struct smb2_hdr *hdr)
 {
     unsigned int i, num = le16_to_cpu(hdr->CreditCharge);

-    hdr->MessageId = get_next_mid64(server);
+    hdr->MessageId = cpu_to_le64(get_next_mid64(server));
     /* skip message numbers according to CreditCharge field */
     for (i = 1; i < num; i++)
         get_next_mid(server);
@@ -490,7 +490,7 @@ smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
         return temp;
     else {
         memset(temp, 0, sizeof(struct mid_q_entry));
-        temp->mid = smb_buffer->MessageId;    /* always LE */
+        temp->mid = le64_to_cpu(smb_buffer->MessageId);
         temp->pid = current->pid;
         temp->command = smb_buffer->Command;    /* Always LE */
         temp->when_alloc = jiffies;
-- 


On Mon, Dec 8, 2014 at 4:30 PM, Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Sachin,
> Since your patch had various sparse warnings, I did a different
> version, basically converting the SMB2/SMB3 MessageID field on the
> wire  to le64 from u64 (we used to assume that the MessageId/MID was
> opaque) and then modifying places that used it to match that
> endianness.
>
> Would you try that and make sure it works in your big endian
> reproduction scenario (or propose an alternate patch)?
>
>
>
> --
> Thanks,
>
> Steve



-- 
Thanks,

Steve

[-- Attachment #2: 0001-SMB2-Fix-SMB2-SMB3-endianness-on-PPC.patch --]
[-- Type: text/x-patch, Size: 4114 bytes --]

From 5f8dedf52a787fa90dcbb7b450a715e3aa487621 Mon Sep 17 00:00:00 2001
From: Steve French <smfrench@gmail.com>
Date: Mon, 8 Dec 2014 16:39:49 -0600
Subject: [PATCH] [SMB2] Fix SMB2/SMB3 endianness on PPC

Redhat had encountered a problem with the SMB2/SMB3 message id (mid)
on PPC - the message id was being considered opaque and endian neutral.
Change the SMB2/SMB3 message id to be le64 on the wire (as we already
do with cifs).

Signed-off-by: Steve French <smfrench@gmail.com>
CC: Sachin Prabhu <sprabhu@redhat.com>
---
 fs/cifs/smb2misc.c      | 12 +++++++-----
 fs/cifs/smb2ops.c       |  2 +-
 fs/cifs/smb2pdu.h       |  2 +-
 fs/cifs/smb2transport.c |  4 ++--
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 1a08a34..6e01933 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -32,12 +32,14 @@
 static int
 check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
 {
+	__u64 wire_mid = le64_to_cpu(hdr->MessageId);
+
 	/*
 	 * Make sure that this really is an SMB, that it is a response,
 	 * and that the message ids match.
 	 */
 	if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
-	    (mid == hdr->MessageId)) {
+	    (mid == wire_mid)) {
 		if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
 			return 0;
 		else {
@@ -51,11 +53,11 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
 		if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
 				 *(unsigned int *) hdr->ProtocolId);
-		if (mid != hdr->MessageId)
+		if (mid != wire_mid)
 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
-				 mid, hdr->MessageId);
+				 mid, wire_mid);
 	}
-	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
+	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
 	return 1;
 }
 
@@ -95,7 +97,7 @@ smb2_check_message(char *buf, unsigned int length)
 {
 	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
 	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
-	__u64 mid = hdr->MessageId;
+	__u64 mid = le64_to_cpu(hdr->MessageId);
 	__u32 len = get_rfc1002_length(buf);
 	__u32 clc_len;  /* calculated length */
 	int command;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 568f323..e5b33d0 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -179,7 +179,7 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf)
 
 	spin_lock(&GlobalMid_Lock);
 	list_for_each_entry(mid, &server->pending_mid_q, qhead) {
-		if ((mid->mid == hdr->MessageId) &&
+		if ((mid->mid == le64_to_cpu(hdr->MessageId)) &&
 		    (mid->mid_state == MID_REQUEST_SUBMITTED) &&
 		    (mid->command == hdr->Command)) {
 			spin_unlock(&GlobalMid_Lock);
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index d84f46c..2d6d388 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -110,7 +110,7 @@ struct smb2_hdr {
 	__le16 CreditRequest;  /* CreditResponse */
 	__le32 Flags;
 	__le32 NextCommand;
-	__u64  MessageId;	/* opaque - so can stay little endian */
+	__le64  MessageId;	/* opaque - so can stay little endian */
 	__le32 ProcessId;
 	__u32  TreeId;		/* opaque - so do not make little endian */
 	__u64  SessionId;	/* opaque - so do not make little endian */
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 5111e72..6bdee1b5 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -468,7 +468,7 @@ smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
 {
 	unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
 
-	hdr->MessageId = get_next_mid64(server);
+	hdr->MessageId = cpu_to_le64(get_next_mid64(server));
 	/* skip message numbers according to CreditCharge field */
 	for (i = 1; i < num; i++)
 		get_next_mid(server);
@@ -490,7 +490,7 @@ smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
 		return temp;
 	else {
 		memset(temp, 0, sizeof(struct mid_q_entry));
-		temp->mid = smb_buffer->MessageId;	/* always LE */
+		temp->mid = le64_to_cpu(smb_buffer->MessageId);
 		temp->pid = current->pid;
 		temp->command = smb_buffer->Command;	/* Always LE */
 		temp->when_alloc = jiffies;
-- 
2.1.0

Re: Revised patch to convert MessageID in smb2_hdr to LE

[Sachin Prabhu]

Hello Steve,

I am working on the patch and in the process of testing it. It is
similar to the patch you have with a few small modifications. I can send
it over as soon as I've tested it on a ppc64 machine.

Sachin Prabhu

On Mon, 2014-12-08 at 16:46 -0600, Steve French wrote:
> Resending (attaching patch)
> 
> Redhat had encountered a problem with the SMB2/SMB3 message id (mid)
> on PPC - the message id was being considered opaque and endian neutral.
> Change the SMB2/SMB3 message id to be le64 on the wire (as we already
> do with cifs).
> 
> Signed-off-by: Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> CC: Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  fs/cifs/smb2misc.c      | 12 +++++++-----
>  fs/cifs/smb2ops.c       |  2 +-
>  fs/cifs/smb2pdu.h       |  2 +-
>  fs/cifs/smb2transport.c |  4 ++--
>  4 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
> index 1a08a34..6e01933 100644
> --- a/fs/cifs/smb2misc.c
> +++ b/fs/cifs/smb2misc.c
> @@ -32,12 +32,14 @@
>  static int
>  check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
>  {
> +    __u64 wire_mid = le64_to_cpu(hdr->MessageId);
> +
>      /*
>       * Make sure that this really is an SMB, that it is a response,
>       * and that the message ids match.
>       */
>      if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
> -        (mid == hdr->MessageId)) {
> +        (mid == wire_mid)) {
>          if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
>              return 0;
>          else {
> @@ -51,11 +53,11 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
>          if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
>              cifs_dbg(VFS, "Bad protocol string signature header %x\n",
>                   *(unsigned int *) hdr->ProtocolId);
> -        if (mid != hdr->MessageId)
> +        if (mid != wire_mid)
>              cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
> -                 mid, hdr->MessageId);
> +                 mid, wire_mid);
>      }
> -    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
> +    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
>      return 1;
>  }
> 
> @@ -95,7 +97,7 @@ smb2_check_message(char *buf, unsigned int length)
>  {
>      struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
>      struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
> -    __u64 mid = hdr->MessageId;
> +    __u64 mid = le64_to_cpu(hdr->MessageId);
>      __u32 len = get_rfc1002_length(buf);
>      __u32 clc_len;  /* calculated length */
>      int command;
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 568f323..e5b33d0 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -179,7 +179,7 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf)
> 
>      spin_lock(&GlobalMid_Lock);
>      list_for_each_entry(mid, &server->pending_mid_q, qhead) {
> -        if ((mid->mid == hdr->MessageId) &&
> +        if ((mid->mid == le64_to_cpu(hdr->MessageId)) &&
>              (mid->mid_state == MID_REQUEST_SUBMITTED) &&
>              (mid->command == hdr->Command)) {
>              spin_unlock(&GlobalMid_Lock);
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index d84f46c..2d6d388 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -110,7 +110,7 @@ struct smb2_hdr {
>      __le16 CreditRequest;  /* CreditResponse */
>      __le32 Flags;
>      __le32 NextCommand;
> -    __u64  MessageId;    /* opaque - so can stay little endian */
> +    __le64  MessageId;    /* opaque - so can stay little endian */
>      __le32 ProcessId;
>      __u32  TreeId;        /* opaque - so do not make little endian */
>      __u64  SessionId;    /* opaque - so do not make little endian */
> diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
> index 5111e72..6bdee1b5 100644
> --- a/fs/cifs/smb2transport.c
> +++ b/fs/cifs/smb2transport.c
> @@ -468,7 +468,7 @@ smb2_seq_num_into_buf(struct TCP_Server_Info
> *server, struct smb2_hdr *hdr)
>  {
>      unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
> 
> -    hdr->MessageId = get_next_mid64(server);
> +    hdr->MessageId = cpu_to_le64(get_next_mid64(server));
>      /* skip message numbers according to CreditCharge field */
>      for (i = 1; i < num; i++)
>          get_next_mid(server);
> @@ -490,7 +490,7 @@ smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
>          return temp;
>      else {
>          memset(temp, 0, sizeof(struct mid_q_entry));
> -        temp->mid = smb_buffer->MessageId;    /* always LE */
> +        temp->mid = le64_to_cpu(smb_buffer->MessageId);
>          temp->pid = current->pid;
>          temp->command = smb_buffer->Command;    /* Always LE */
>          temp->when_alloc = jiffies;
> -- 
> 
> 
> On Mon, Dec 8, 2014 at 4:30 PM, Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > Sachin,
> > Since your patch had various sparse warnings, I did a different
> > version, basically converting the SMB2/SMB3 MessageID field on the
> > wire  to le64 from u64 (we used to assume that the MessageId/MID was
> > opaque) and then modifying places that used it to match that
> > endianness.
> >
> > Would you try that and make sure it works in your big endian
> > reproduction scenario (or propose an alternate patch)?
> >
> >
> >
> > --
> > Thanks,
> >
> > Steve
> 
> 
> 

Re: Revised patch to convert MessageID in smb2_hdr to LE

[Sachin Prabhu]

On Mon, 2014-12-08 at 16:46 -0600, Steve French wrote:
> Resending (attaching patch)
> 
> Redhat had encountered a problem with the SMB2/SMB3 message id (mid)
> on PPC - the message id was being considered opaque and endian neutral.
> Change the SMB2/SMB3 message id to be le64 on the wire (as we already
> do with cifs).
> 
> Signed-off-by: Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> CC: Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Hello Steve,

The patch is very similar to the patch I've created. Testing took time
since I had to first provision a ppc64 machine and then recompile the
rawhide kernel for it since ppc64 isn't available in rawhide. 

I've documented the differences between my patch and the patch you
proposed inline.

> ---
>  fs/cifs/smb2misc.c      | 12 +++++++-----
>  fs/cifs/smb2ops.c       |  2 +-
>  fs/cifs/smb2pdu.h       |  2 +-
>  fs/cifs/smb2transport.c |  4 ++--
>  4 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
> index 1a08a34..6e01933 100644
> --- a/fs/cifs/smb2misc.c
> +++ b/fs/cifs/smb2misc.c
> @@ -32,12 +32,14 @@
>  static int
>  check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
>  {
> +    __u64 wire_mid = le64_to_cpu(hdr->MessageId);
> +
>      /*
>       * Make sure that this really is an SMB, that it is a response,
>       * and that the message ids match.
>       */
>      if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
> -        (mid == hdr->MessageId)) {
> +        (mid == wire_mid)) {
>          if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
>              return 0;
>          else {
> @@ -51,11 +53,11 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
>          if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
>              cifs_dbg(VFS, "Bad protocol string signature header %x\n",
>                   *(unsigned int *) hdr->ProtocolId);
> -        if (mid != hdr->MessageId)
> +        if (mid != wire_mid)
>              cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
> -                 mid, hdr->MessageId);
> +                 mid, wire_mid);
>      }
> -    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
> +    cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
>      return 1;
>  }
> 
> @@ -95,7 +97,7 @@ smb2_check_message(char *buf, unsigned int length)
>  {
>      struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
>      struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
> -    __u64 mid = hdr->MessageId;
> +    __u64 mid = le64_to_cpu(hdr->MessageId);
>      __u32 len = get_rfc1002_length(buf);
>      __u32 clc_len;  /* calculated length */
>      int command;

My earlier version of the patch changed the type for the argument mid in
check_smb2_hdr() from __u64 to __le64 and changes were made accordingly.
Your version looks better. So I've used this in my patch too.

> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 568f323..e5b33d0 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -179,7 +179,7 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf)
> 
>      spin_lock(&GlobalMid_Lock);
>      list_for_each_entry(mid, &server->pending_mid_q, qhead) {
> -        if ((mid->mid == hdr->MessageId) &&
> +        if ((mid->mid == le64_to_cpu(hdr->MessageId)) &&

Don't know if this matters much but I've used a temp varialble which
holds the value for le64_to_cpu(hdr->MessageId) and uses that for
comparison in the loop instead.

>              (mid->mid_state == MID_REQUEST_SUBMITTED) &&
>              (mid->command == hdr->Command)) {
>              spin_unlock(&GlobalMid_Lock);
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index d84f46c..2d6d388 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -110,7 +110,7 @@ struct smb2_hdr {
>      __le16 CreditRequest;  /* CreditResponse */
>      __le32 Flags;
>      __le32 NextCommand;
> -    __u64  MessageId;    /* opaque - so can stay little endian */
> +    __le64  MessageId;    /* opaque - so can stay little endian */
I've removed the comment since it doesn't appear to be opaque.

>      __le32 ProcessId;
>      __u32  TreeId;        /* opaque - so do not make little endian */
>      __u64  SessionId;    /* opaque - so do not make little endian */
> diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
> index 5111e72..6bdee1b5 100644
> --- a/fs/cifs/smb2transport.c
> +++ b/fs/cifs/smb2transport.c
> @@ -468,7 +468,7 @@ smb2_seq_num_into_buf(struct TCP_Server_Info
> *server, struct smb2_hdr *hdr)
>  {
>      unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
> 
> -    hdr->MessageId = get_next_mid64(server);
> +    hdr->MessageId = cpu_to_le64(get_next_mid64(server));

get_next_mid() already returns the MID in little endian form. To be
consistent, get_next_mid64() should also return the MID in little
endian.


>      /* skip message numbers according to CreditCharge field */
>      for (i = 1; i < num; i++)
>          get_next_mid(server);
> @@ -490,7 +490,7 @@ smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
>          return temp;
>      else {
>          memset(temp, 0, sizeof(struct mid_q_entry));
> -        temp->mid = smb_buffer->MessageId;    /* always LE */
> +        temp->mid = le64_to_cpu(smb_buffer->MessageId);
>          temp->pid = current->pid;
>          temp->command = smb_buffer->Command;    /* Always LE */
>          temp->when_alloc = jiffies;
> -- 
> 

I've also tested your version of the patch. The client was able to mount
and perform a few simple tasks as required.

The new version(v3) of the patch I had written was successfully tested
on a ppc64 machine. I will send my version (v3) of the patch to the
mailing-list.

Sachin Prabhu